I venture that the Galactica and the fleet must have either gone faster than the speed of light to escape from their pursuers to arrive at the earth in the opening episode of Galactica 80 after receiving the Apollo signal in Hand of god or they went back in time and had a longer trip than was necessary! Troy's age would be thirty I guess and as Boxey maybe seven or eight or even younger, so that means the whole voyage may have taken twenty to twenty five earth years but if Hand of God was at the end of the first or second year in space, and the signal only recently sent then ten or eleven years was a greater difference to the crew of The Galactica than it would be to the peoples of the earth!
JB

Agree, that "Hand Of God" episode's NASA Apollo transmission would in fact mean that Galactica:1980 was only about one decade away.

So, it is a major gaffe.

Maybe a time warp "science-fiction" excuse will help. They can explain it away by saying that the NASA Apollo transmission passed through a temporal rift from twenty years in the future meaning at the time "Hand Of God" happened it was around 1949 Earth year. Although, it originated from a future Earth year of 1969.

Agree, they should have arrived in 1990. They probably did not to avoid budget limitations if they had to depict changes made ten years out as Gerry Anderson's UFO(1970-1973) did depicting it's 1980 setting.
If, as you suggested, they arrived in 1990 and then used their time traveling Vipers to go back to 1980 to visit Earth ten years before the Cylon fleet arrives following their Colonial fleet in 1990 to prepare the Earth's defense...
I loved the 2-seat time-warping Viper complete with both forceshield invisibility and a flying Turbine stored in it's carghold. I think that the Galactica:1980 series should have been about Colonial Vipers time traveling to explore Earth's history [and chase Xavier or a Cylon(s)] as was established in the pilot "Galactica Discovers Earth", but sadly abandoned.